Nope, haven't heard this. It would be cool, but kinda defeats the purpose of having the hp/tq. I would like to see how exactly they do this and if it is truely possible. I'm pretty happy with my fuel economy. I went from a 5.3 that I could barely get 300 miles to a tank on the highway to this truck that will get nearly 500 miles to a tank. (same size tank) Both figures are unloaded.
Heard nothing whatsoever, but electronic injectors should be capable of computer control to turn off a few at a time. Sure would help the empty cruising mpg at highway speeds. Turning off 4 injecters would still leave approx. 150 HP from the other 4 working cylinders, in theory halving your fuel useage and rule out passing that Morris Minor in front of you.
I'm not so sure that this would work on a diesel to increase fuel economy. Just shutting off the injectors would still allow the non functioning cylinders to compress air with would take work. Dodge used to do this on there older 5.9's in cold climates for the idle. The extra load of the 3 cylinders not firing allowed the engine to warm faster as the remaining 3 had to work harder. This is also used in marine but just for warm-up as well